The purpose of this project is to establish the range of pathologic alterations in the hearts of HIV infected subjects in two distinct autopsy populations; 1) autopsies performed on individuals dying with a full manifestation of the disease in a large county hospital and 2) HIV seropositive individuals autopsied in an active medical examiners's office. The latter group comprises 1) asymptomatic HIV seropositive subjects; 2) ARC subjects; and 3) AIDS subjects. It is anticipated that assessment of the incidence, topography and nature of the cardiac lesions will provide an insight regarding the onset and evolution of the disease and the functional cardiac disturbances that may accompany the pathologic lesions. Both the working myocardium and cardiac conduction system of HIV seropositive individuals and controls will be examined with routine histologic techniques. In those cases where lesions are discovered, further characterization of the lesions and responsible eitologic agents will be done using special histologic techniques including immunohistochemistry. Viral isolation, in-situ DNA hybridization and ultrastructural studies will be done in cardiac tissues from selected cases to identify HIV and its possible association with inflammatory lesions of the heart. On the basis of our prior studies, it is expected that about 50% of HIV seropositive subjects and about 0.5% of the controls will exhibit histologic lesions. Final analysis of the data will be conducted with the goal of achieving insights into the best treatment strategies for the alterations found whether protozoal, fungal, viral or of undertermined nature. Also, the potential use of endomyocardial biopsy for specific diagnosis will be explored.